idnits 2.17.1 draft-ietf-issll-rsvp-cap-00.txt: ** The Abstract section seems to be numbered Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- ** The document seems to lack a 1id_guidelines paragraph about 6 months document validity -- however, there's a paragraph with a matching beginning. Boilerplate error? == No 'Intended status' indicated for this document; assuming Proposed Standard == The page length should not exceed 58 lines per page, but there was 4 longer pages, the longest (page 4) being 65 lines == It seems as if not all pages are separated by form feeds - found 0 form feeds but 6 pages Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack a Security Considerations section. ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) ** There are 61 instances of too long lines in the document, the longest one being 5 characters in excess of 72. ** There are 16 instances of lines with control characters in the document. ** The abstract seems to contain references ([DCLASS]), which it shouldn't. Please replace those with straight textual mentions of the documents in question. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == Line 95 has weird spacing: '...ability may h...' -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- Couldn't find a document date in the document -- date freshness check skipped. Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) -- Missing reference section? 'DCLASS' on line 294 looks like a reference -- Missing reference section? 'RSVP' on line 291 looks like a reference -- Missing reference section? 'DS' on line 286 looks like a reference -- Missing reference section? 'INTDIFF' on line 282 looks like a reference Summary: 8 errors (**), 0 flaws (~~), 5 warnings (==), 6 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 1 draft-ietf-issll-rsvp-cap-00.txt 3 Internet Draft Syed, Hamid, 4 draft-ietf-issll-rsvp-cap-00.txt Nortel Networks 6 September, 2000 8 Capability Negotiation: The RSVP CAP Object 10 Status of this Memo 12 This document is an Internet-Draft and is in full conformance with all 13 provisions of Section 10 of RFC2026. 15 Internet-Drafts are working documents of the Internet Engineering Task 16 Force (IETF), its areas, and its working groups. Note that other groups 17 may also distribute working documents as Internet-Drafts. 19 Internet-Drafts are draft documents valid for a maximum of six months 20 and may be updated, replaced, or obsoleted by other documents at any 21 time. It is inappropriate to use Internet- Drafts as reference material 22 or to cite them other than as "work in progress." 24 The list of current Internet-Drafts can be accessed at 25 http://www.ietf.org/ietf/1id-abstracts.txt 26 The list of Internet-Draft Shadow Directories can be accessed at 27 http://www.ietf.org/shadow.html. 29 Distribution of this memo is unlimited. 31 Copyright Notice 33 Copyright (C) The Internet Society (2000). All Rights Reserved. 35 1. Abstract 37 The DCLASS object is proposed in [DCLASS] to represent and carry 38 Differentiated Services Code Points (DSCPs) within RSVP messages. The 39 principle use of the DCLASS object is to carry DSCP information 40 between a DS network and upstream nodes that may wish to mark packets 41 with DSCP values. A network element in the DS network determines the 42 value for DSCP which is further carried as a DCLASS object in RSVP 43 RESV message to the sender host. 45 There may be situations where the sender host is not capable or may 46 not wish to mark the packets. Currently, there is no way for the 47 host or network devices to specify their capabilities to the upstream 48 nodes. 50 This draft proposes a capability object (CAP object) in the RSVP PATH 51 message that can be used to convey end host/downstream node 52 capabilities to the upstream network. It also defines one bit in the 53 CAP field of the CAP object to convey the host/downstream node's 55 draft-ietf-issll-rsvp-cap-00.txt September, 2000 57 marking capability/willingness for accepting a DCLASS object from the 58 upstream network and marking the upstream packets. 60 2. Introduction 62 The mechanics of using RSVP [RSVP] signalling and the DCLASS object 63 for requesting and applying the QoS in a differentiated services [DS] 64 network is described fully in [INTDIFF]. It assumes an architecture 65 with RSVP senders and receivers and a differentiated services network 66 somewhere between the sender and the receiver. At least one RSVP aware 67 network element resides in the diff-serv network. This network element 68 interacts with RSVP messages arriving from outside the DS network. 70 The principle use of the DCLASS object is to carry DSCP information 71 between a DS network and upstream nodes that may wish to mark packets 72 with DSCP values. A network element in the DS network determines the 73 value for DSCP which is further carried as a DCLASS object in RSVP 74 RESV message to the sender host. If the network element determines 75 that the request represented by the PATH and RESV messages is 76 admissible to the diff-serv network, a desision is made to mark the 77 arriving data packets for this traffic using MF classification, or 78 to request upstream marking of packets with the appropriate DSCPs. 79 If the network element decides the packets to be marked at the sender 80 host for the data traffic, it adds a DCLASS object in the RSVP RESV 81 message to the host. The use and format of DCLASS object is fully 82 specified in [DCLASS]. 84 There may be situations where the sender host is not capable or may 85 not wish to mark the packets. In the current definition of DCLASS 86 object, the network edge device inserts the DCLASS object in the RSVP 87 RESV message without having any prior knowledge of the host capability 88 whether or not the host can make use of this object. This is one 89 example where the network element needs to know the host capabilities 90 before making a policy decision. Moreover, the definition of DCLASS 91 object allows any DS domain to supply DCLASS object on a flow to the 92 downstream DS domains. A prior knowledge of the downstream DS domain's 93 marking capability could be useful for the upstream DS domain. There 94 could be other scenerios where an advance knowledge of the host or a 95 downstream node's capability may help the network to provide better 96 policy decisions to the end host. Currently, there is no way for the 97 host or network devices to specify their capabilities. 99 The decision where the data packets should be marked can be made at the 100 DS network nodes assuming that the network edge devices have a prior 101 knowledge of the marking capability of the downstream domains. 102 Section 3 of this draft describes two scenarios to explain the use of 103 CAP object in RSVP PATH message. 105 3. Capability Negotiation 107 The capability object called 'CAP' object can be used as a mechanism 108 for conveying node capabilities or willingness in RSVP messages. As an 109 example, we will focus on the marking capability of nodes throughout 110 this document and define a single bit for host marking information to 111 be carried in the CAP field inside the CAP object of RSVP PATH message. 113 draft-ietf-issll-rsvp-cap-00.txt September, 2000 115 However, the CAP is a generic object that can be used to carry any other 116 meaningful capability information in the RSVP PATH message. To explain 117 the use of CAP object in RSVP PATH message, we will describe two 118 scenarios 120 - Host-Edge router interaction 121 - Border Router-Border Router interaction 123 It should be noted that how and when the packets will be marked is a 124 decision governed by the network policies. The network policy domain 125 may or may not trust the end host marking. Hence, even though the network 126 may have supplied the DCLASS object to the end host on request (via CAP) 127 it may overwrite the marking based on the domain policy. 129 3.1 Host-Edge Router Capbility Negotiation 131 The advance knowledge of the end host's capabilities may help the 132 network edge devices to make policy decisions on end host's requests. 133 These capabilities can be indicated in the RSVP PATH message to the 134 upstream edge devices. 136 The end hosts can be classiffied in two categories: Those capable of 137 marking upstream packets and decide to do so. The other category of 138 hosts either do not have the capability to mark packets or they decide 139 not to mark packets. In either case, the network element needs to know 140 the host packet marking capability/willingness. This information can 141 help the network element to decide whether or not a DCLASS object must 142 be added in a RSVP message for the flow. One way to convey the host 143 capability/willingness to the network is to use the RSVP PATH message. 144 We give examples here to explain the scenarios. 146 If the sender host is ready to mark the upstream traffic (based on the 147 DCLASS provided by the network element), it sets the marking bit of the 148 CAP field inside the CAP object of the RSVP PATH message. On receiving 149 the RSVP message, the network element at the DS edge records the host 150 marking capability as the PATH state. It then resets the marking bit and 151 sends the RSVP message to the upstream nodes. The treatment of the CAP 152 object at the upstream nodes will be explained in next section. For now, 153 consider the RESV message comes back to the edge device, it performs the 154 necessary admission control. If the network element determines that the 155 request represented by the PATH and RESV messages is admissible to the 156 diff-serv network, it adds a DCLASS object after consulting the recorded 157 state. It may decide to overwrite any DCLASS object inserted by the 158 an upstream node/domain based on its own domain policies. This is exactly 159 how the DCLASS object is defined. 161 Another example could be the end host that is not capable of upstream 162 packet marking. This either will not include a CAP object or the host 163 will reset the marking bit of the CAP object as an indication of his 164 unwillingness of packet marking. The network edge router will then know 165 that the downstream node/end host does not require a DCLASS object. The 166 edge router, in this case, would be responsible for marking the upstream 167 packets from the end host. 169 draft-ietf-issll-rsvp-cap-00.txt September, 2000 171 3.2 Boundry router-Boundry Router Interaction 173 The CAP object could be carried in the PATH message end-to-end. The RSVP 174 PATH message is generated by the end host. The network edge router 'A' 175 of the DS domain processes the message, resets the marking bit of the 176 CAP object (if it comes as set from the host) and passes the PATH message 177 to the next RSVP Hop. For a DS domain, the boundray router 'B' of the 178 access/stub network receives the RSVP PATH message as next RSVP enabled 179 node (Figure 1). It may set the marking bit again to advertise the marking 180 capability of its own domain. The decision must be governed by the domain 181 policy. The ingress boundary router 'C' of the upstream domain receives 182 the CAP object with the marking bit set providing an indication of the 183 marking capability of the downstream node/domain. It again stores this 184 information as the PATH state, resets the marking bit and passes it to 185 the upstream RSVP enabled network element. The boundary router 'D' of 186 this domain may decide to set the marking bit again based on the domain 187 policy. The PATH message may pass through more domains like this until 188 it is received by the host. The RSVP RESV message is then generated and 189 passed through the same route. The RSVP message arrives at the the 190 router 'C' and it may contain a DCLASS object provided by an upstream 191 node/domain. The PATH state of router 'C' indicates that the downstream 192 node/domain is capable of packet marking and a DCLASS object is to be 193 passed back. The domain policy/admission control decisions of router 'C' 194 may not allow the router to use the same DCLASS value as it received 195 from the upstream. So it may decide to overwrite the DCLASS value. The 196 edge router 'A' may also decide to remark the DCLASS value in the RESV 197 message following its admission control outcome and knowing the end 198 host's willingness for packet marking. Finally, the end host receives 199 the DCLASS value in RESV message and it may start marking the upstream 200 packets with the appropriate DSCP. 202 Once again, It should be noted that how and when the packets will be 203 marked is a decision governed by the network policies. The network 204 policy domain may or may not trust the end host marking. Hence, even 205 though the network may have supplied the DCLASS object to the end host 206 on request (via CAP) it may overwrite the marking based on the domain 207 policy. 209 +----------+ +-----------+ 210 |DS domain | |DS domain | 211 | 1 | | 2 | 212 +----+ +----+ +----+ +----+ +----+ +----+ 213 |Host|-----| A | | B |----| C | | D |---''''''|Host| 214 +----+ +----+ +----+ +----+ +----+ +----+ 215 | | | | 216 | | | | 217 +----------+ +-----------+ 219 Figure 1 221 4. Format of CAP Object 223 The CAP object has the following format: 225 0 | 1 | 2 | 3 226 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 227 | Length | C-Num (226) | C-Type=1 | 228 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 229 | CAP field | 230 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 232 draft-ietf-issll-rsvp-cap-00.txt September, 2000 234 CAP field: 236 0x01: D_MARK 237 The host marking capability/willingness identifier. 238 If D_MARK bit is reset, the sender host/downstream node 239 is not able to mark packets 240 If D_MARK bit is set, the sender host/Downstream node is 241 able/willing to mark packets 243 Note: D_MARK is a bit in the CAP (capbility) field. 245 5. Deployment Scenarios 247 There are a number of hosts today which do have the marking capability 248 and they even do not depend on a DCLASS object from the network. The 249 marking is based on a default mapping from requested service type to 250 the DSCP. In this section, we will briefly address the deployment 251 scenarios for such hosts which do mark without signaling network 252 about their marking capability. 254 If a host does not provide an CAP object, then the network edge must 255 be provisioned (or be given policies) as to how it should react. This 256 may be one of: 257 - send a DCLASS object. 258 - install a filter to mark the appropriate flow at the edge. 259 - do both. 260 The problem here is ensuring that the mapping configured in the host 261 matches the allowed mappings configured in the edge router. If there 262 is a mismatch, the edge router will, at best, remark the packets to 263 match its policies (possibly resulting in a treatment different from 264 that expected by the host) or, at worst, mark packets as non-conforming 265 and discard them. The policy may be for a specific host address, for 266 a specific interface, for a specific edge router or for the entire 267 domain. The bottom line is that manual provisioning would be required 268 in the interim until hosts support the CAP option. Once hosts support 269 the CAP option, manual provisioning would no longer be required. 271 In a multi-domain scenario, the boundary router 'B' could be the first 272 and the only router in the first DS domain who is dealing with the 273 CAP/DCLASS objects (maintaining the state information and deciding for 274 a DSCP for the downstream end host). This will allow only one router 275 in a domain with the knowledge of the host's capability and will be 276 the one responsible for deciding/providing a DCLASS object in a RSVP 277 RESV message. In this scenario, the boundary router 'B' becomes the DS 278 edge for the end host. 280 6. References 282 [INTDIFF], Bernet, Y., Yavatkar, R., Ford, P., Baker, F., Zhang, L., 283 Speer, M., Braden, R., Davie, B., Wroclawski, J., "Integrated Services 284 Operation over Diffserv Networks", Internet Draft, June 1999 286 [DS] An Architecture for Differentiated Services. S. Blake, D. Black, 287 M. Carlson, E. Davies, Z. Wang, W. Weiss, RFC 2475, December 1998. 289 draft-ietf-issll-rsvp-cap-00.txt September, 2000 291 [RSVP] Braden, R. ed., "Resource ReSerVation Protocol (RSVP) - 292 Functional Specification.", IETF RFC 2205, Sep. 1997. 294 [DCLASS] Bernet, Y., "Format of the RSVP DCLASS Object", 295 IETF , Oct., 1999. 297 6. Acknowledgments 299 Thanks to Bill Gage, Yoram Bernet, Goran Janevski, Gary Kenward, 300 kwok Ho chan, Muhammad Jaseemuddin and Louis-Nicolas Hamer for 301 reviewing this draft and providing useful input. 303 7. Author's Address 305 Syed, Hamid 306 Nortel Networks 307 100 - Constellation Crescent, 308 Nepean, ON K2G 6J8 309 Phone: (613) 763-6553 310 Email: hmsyed@nortelnetworks.com 312 8. Full Copyright Statement 314 "Copyright (C) The Internet Society (date). All Rights Reserved. 315 This document and translations of it may be copied and furnished to 316 others, and derivative works that comment on or otherwise explain it 317 or assist in its implementation may be prepared, copied, published 318 and distributed, in whole or in part, without restriction of any 319 kind, provided that the above copyright notice and this paragraph 320 are included on all such copies and derivative works. However, this 321 document itself may not be modified in any way, such as by removing 322 the copyright notice or references to the Internet Society or other 323 Internet organisations, except as needed for the purpose of 324 developing Internet standards in which case the procedures for 325 copyrights defined in the Internet Standards process must be 326 followed, or as required to translate it into languages other than 327 English. 329 The limited permissions granted above are perpetual and will not be 330 revoked by the Internet Society or its successors or assigns. 332 This document and the information contained herein is provided on an 333 "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING 334 TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT 335 NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN 336 WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF 337 MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 339 draft-ietf-issll-rsvp-cap-00.txt September, 2000